Core for use in the manufacture of furniture and method of manufacture of core

ABSTRACT

A core for use in the manufacture of furniture which comprises a plurality of superimposed thin, flexible sheets which have been adhesively secured together, and then formed into a U-shaped core, with the core being used in the manufacture of furniture, for instance, as the backing portion of a chair. The core is manufactured by superimposing a plurality of thin, flexible sheets, one upon the other, by high speed equipment, and simultaneously applying adhesive to the sheets as the superimposition process proceeds to form a stack. The stack is then positioned in matched pressure dies and with the action of pressure the core of the present invention is formed into a U-shape, although many other shapes are contemplated.

[72] Inventors Henry Baudremer 1435 Hagys Ford Road, Nat-berth, Pa.19072; Irving L. Bandremer, 1214 Sandringham Road, Bala Cynwyd, Pa.19004 [21] Appl. No. 872,601 [22] Filed Oct. 30, 1969 [45] Patented Oct.26, 1971 [54] CORE FOR USE IN THE MANUFACTURE OF FURNITURE AND METHOD OFMANUFACTURE OF CORE 6 Claims, 18 Drawing Figs. [52] US. Cl 156/90,156/212 [51] Int. Cl B32b 33/00 [50] Field of Search 156/90, 196, 212 56] References Cited UNITED STATES PATENTS 2,288,293 6/1942 Metcalf156/90 2,395,468 2/1946 Eames 2,543,858 3/1951 Linda PrimaryExaminer-Carl D. Quarforth Assistant Examiner-S, R. HellmanAttorney-Caesar, Rivise, Bernstein & Cohen ABSTRACT: A core for use inthe manufacture of furniture which comprises a plurality of superimposedthin, flexible PKTENTEDnm 2s 19?:

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sum u 0F 4 wavemons. HENRY BANDREMER ATTORNEYS.

l. L. BANDREMER CORE FOR USE IN THE MANUFACTURE OF FURNITURE AND METHODOF MANUFACTURE OF CORE This invention relates to a core for use in themanufacture of furniture like chairs, and also to the method ofmanufacture of the core. The product of the present invention may alsobe used in making desks or the manufacture of nonfumiture items, forinstance, articles in the aircraft or automotive field, like bucketseats, or anywhere else where free form curves are to be produced as inwall separators or in cement forms. Thus, the term fumiture" as usedherein is to be given a broader meaning.

In the manufacture of furniture it is the practice to assemble togethercertain basic components which are then provided with a finishedcovering or coating in order to complete the steps of manufacture. Manyitems of furniture are built up from a basic frame or a core memberwhich is an essential feature of the particular article of furniture.

For instance, in the manufacture of certain types of chairs, it is thepractice to provide a curved core member which is attached to a seat orbottom, prior to the application of upholstery or other finishedmaterial. For a long time the core member was made from plywood, butplywood suffered from a certain lack of flexibility which complicatedany process for making a curved core member.

With the steep rise in the price of plywood, this material became evenless desirable, and hence the search intensified for a substitute forthe plywood.

Although a multilayer chair shell was taught in Yellen US. Pat. No.3,033,732, this item has not won wide acceptance in the trade. TheYellen shell was manufactured by laying up a series of blanks by handupon a jig. Such a process is not only time consuming but necessitates aconsiderable amount of adhesive which renders the Yellen process morecostly in view of the necessity to allow sufficient time for theadhesive to dry.

It is therefore an object of the present invention to provide a methodof manufacture of a core which is not only an effective substitute forplywood, but also can be manufactured quickly and economically.

Still another object of the present invention is to provide a finishedcore which will not only possess the requisite characteristics ofstrength and rigidity, at minimum cost, but also which will prove to beresistant to mildew and similar agents of deterioration, for the life ofthe article of furniture in which the core is used. r

The foregoing as well as other objects of the invention are achieved byproviding a core which is manufactured from a plurality of properlyprepared, superimposed flexible sheets, such as cardboard, whichiaf eadhesively secured together by automatic processing equipment to form astack wherein the adhesive penetrates only for amount sufi'icient togain a good grip. Following this assembly step, the stack thus fonned islaid upon matched pressure dies which then form the laminate into aparticular shape of core member, such as a U- shape It will be seen thattheprocess of the invention may be carried out rather rapidly since thesteps of superimposition and adhesive securement proceed rather rapidly,particularly because of the use of automatic equipment which feeds theflexible pieces one-by-one to achieve a stack of superimposed flexiblemembers that have been adhesively coated during the feeding process, sothat the stack is quickly united into a single mass.

With proper application of adhesive and proper surface preparation ofthe flexible members, the drying time is very short, and there is noescape of adhesive from between the superimposed sheets. Thus, handlingof the solidified stack and transporting it to the mold proceeds easilyand cleanly. Following the molding process the core may be trimmed toany desired shape.

Other objects and many of the attendant advantages of the invention willbecome readily apparent by reference to the appended drawings wherein:

FIG. I is a perspective view showing an example of matched pressure diesthat may be used to shape the stack of superimposed flexible sheets thathave been provided in accordance with an earlier step of the process ofthe present invention;

FIG. 2-A is an enlarged sectional view taken along the lines 2-2 of FIG.1;

FIG. 2-B is a schematic view showing automatic feeding and adhesiveapplicator apparatus usable in the practice of the present invention;

FIG. 3 is a side elevational view of the molding apparatus of FIG. 1,with certain portions omitted for the sake of clarity, showing the maleand female members of the matched pressure dies, with a superimposedstack of flexible members schematically shown in relation thereto;

FIG. 4 is a view similar to FIG. 3 wherein the female member hasadvanced upwardly;

FIG. 5 is a perspective view of a core blank produced in accordance withthe process of the present invention;

FIG. 6 is a greatly enlarged sectional view taken along the lines 6-6 ofFIG. 3, and showing the stack of superimposed flexible sheets prior tothe pressure step;

FIG. 7 is a view similar to FIG. 5 but wherein the core blank of FIG. 5has been cut into two cores which may now be used in the manufacture offurniture;

FIG. 8 is a view similar to FIG. 7 showing one of the cores of thepresent invention about to be united with other components to produce achair;

FIG. 9 is a view similar to FIG. 8, but wherein cushioning material hasbeen applied and stapled to the core member of FIG. 8;

FIG. 10 is a perspective view of a chair having a backing member whichutilizes the intermediate product of FIG. 9 which is subsequentlycovered with a finished material;

FIG. II is a perspective view of another chair which is manufacturedwith a backing produced by the process of the present invention, andwhich also includes a detachable backing member that is made usinganother type of core member that is manufactured in accordance with theprocess of the present inventidh;

FIG. 12 is a perspective view of the chair of FIG. I I wherein theauxiliary backirig member has been secured upon the chair;

FIG. 13 is an enlarged sectional view taken along the lines l3-l3 ofFIG.12;

FIGS. 14 and 15 are perspective views of other chairs (legs not shown)which include backings that are made from core members produced by theprocess of the present invention; and

FIGS. 16 and 17 are schematic views showing variations of pressure diesused in the present invention.

Referring now in greater detail to the various figures of the drawingwherein like reference characters refer to like parts there is shown atl0 in FIG. I matched pressure dies which are used to produce a coremember of the present invention. The apparatus 10 is generally of wellknown-construction, and so only the basic details thereof will bediscussed here.

The apparatus I0 comprises the usual posts 12 extending from fixed upperframe 14 and movable lower frame 16, which is movable lipwardly as willbe discussed hereinafter, as allowed by the posts 12. As can be seen inFIG. 1 a fixed male part 18 extends downwardly toward upwardly movablefemale part 20. This movement can be observed by comparing FIGS. 3 and 4as will be discussed hereinafter. If desired the male part can bemovable, and the female part fixed.

Further details of the apparatus I0 can also be seen in FIG. 2-A. Sincethe details of this apparatus are rather conventional, such details willbe readily recognizable in FIGS. 1 and 2-A.

As can be seen in FIG. Z-B, automatic feeding and adhesive applicatorapparatus is utilized. It wilLbe seen that thin, flexible sheets 22 arefed one-by-one by automatic transport equipment to adhesive applicator24 which basically involves closely spaced rollers 24-A and 24-8, withthe latter roller extending into a well or container 24-C of adhesive.In this way, adhesive is applied only to the lower surface of one of theflexible sheets 22.

It will further be seen from FIG. 2-B that the flexible sheets 22 arethen deposited upon a pad 26. Since the adhesive is automaticallyapplied to the lower surface of each of the flexible sheets 22, itfollows that the very first or lowermost sheet 22 should be placedautomatically or manually upon the pad 26 without the application ofadhesive. Then, the next flexible sheet 22 with a coating of adhesive onits lower surface is deposited upon the first flexible sheet, and so onuntil a stack 28 of flexible members is built up to a desired height. Ifdesired the adhesive can be applied only to the top surface or to bothsurfaces or portions thereof.

The flexible sheets used in the present invention are preferably ofabout 1/16 inch to 14; inch thick and are of cardboard like Kraft paperor chipboard. It is desired that the cardboard include an antimildewagent such as a eresol, a phenol or formaldehyde in a small, buteffective amount of about l/lO of 1 percent. The adhesive to be used inthe practice of the present invention is tacky at ordinary roomtemperature, and preferably will set in a period of one minute or lessat room temperature. An example of an adhesive that has beensuccessfully used in the practive of the present invention is atackified polyvinyl alcohol adhesive, combined with inert material whichhas the following properties:

a. white color b. pH 4.4 to 4.8

c. mesh 325 d. particle shape thin, flat plate e. coated with 0.5percent stearate The foregoing adhesive also includes a defoamer, andcontains polyvinyl acetate and a thermoplastic resin. The variouscomponents are dispersed in cold water and heated to 200 F. to completesolution, and then are cooled to 100 F., with the viscosity and pH beingadjusted before packaging into drums.

It is quite important that the surface of the flexible sheets used inthe present invention be properly prepared. The sheets should be sofinished as to have a smooth surface. Furthermore, a sizing coating isto have been applied to such surface in order to lessen but not fullyeliminate the absorptive properties of the surface. In this way somepenetration of the adhesive occurs, and thus the adhesive, when set, isan effective bonding agent. However, penetration of large amounts of theadhesive or saturation of adhesive in the flexible sheets is avoided.Thus with the present invention the stack dries or sets rather quickly,usually in less than one minute.

It will be seen that the stack 28 of FIG. 2-B is formed rather easily,and is simply handled. With proper application of adhesive and propersurface preparation as detailed hereinabove, there is no mess. Theoperator simply lifts the stack 28 from the pad 26 and places the stack28 on the female member 20 of the dies I as schematically shown in FIG.3. Of course, automatic transport and handling equipment may be providedto carry the stack 28 from the pad 26 to the female member of FIG. 3. Itwill be appreciated that the action of the dies causes pressure to forcethe adhesive further into the flexible members.

It can be seen in FIG. 6 that the stack 28 is comprised of a series offlexible members 22. As shown in FIG. 4 the female member 20 advancesupwardly in the direction of arrow 30 in order to produce core blank 32of FIG. 5. It will be seen that the core blank 32 is U-shaped with legs34 extending from a base section 36.

Of course, other configurations of the core blank 32 can be manufactured(see FIGS. 16 and 17) depending upon the particular configuration of themembers 18 and 20 as determined by the desired configuration of theultimate core to be produced. Thus, the core blank 32 is only exemplaryof the core that can be made in accordance with the process of thepresent invention.

As can be seen in FIG. 7 a core 38 is simply cut out using template 39,with support bar 39-A, in accordance with a pattern 50 from the coreblank 32. Again, the particular configuration of the core 38 can bewidely varied depending upon the desired shape of the finished productjust as the wide latitude of materials and physical conditions that areinherent in the present invention.

It will be seen that the properties of these materials and conditionscan be varied in order to provide a more or less rigid final product orto impart other properties of interest to the final product.

The uses of the core 38 of FIG. 8 can be seen by reference to remainingfigures 9 to [5 of the drawing.

In FIG. 9 a cushioning material 42 has been applied and stapled to thecore member 38.

In FIG. 10 the intermediate product of FIG. 9 has been subsequentlycovered with a finished material 44 (with suitable upholstering) andthen applied to a pedestal 46 in order to complete the manufacture of achair.

FIG. 11 shows another chair that is manufactured using a backing 48 thathas been produced from a different core which was manufactured inaccordance with the present in vention. Here the backing member 48 isdetachable, and has been provided with a cushioning material and afinished covering. In FIG. 1] the rear portion of the core backing 48 isvisible, and is shown to have been provided with openings 50 that fitabout fasteners 52 that project from the back 54 of the chair 56 of FIG.11. It will be seen that the back 54 is made from a core 38 of FIG. 8.The completed chair of FIG. II is shown at 60 in FIG. 12, with thedetails of the backing 48 being visible at FIG. 13 including cushioningmaterial 62 and covering 64.

Also, reference is made to FIGS. 14 and 15 which show other chairs thatinclude backs made from cores produced in accordance with the presentinvention. It will be seen that FIG. 14 shows a low silhouette chair 66with a back that is somewhat shorter and wider than would be obtainedwith the core 38 of FIG. 8. FIG. 15 shows a chair 68 with a tall back.

With reference to FIGS. 16 and 17 there will be seen schematic viewsshowing variations of pressure dies used in the present invention.

FIG. 16 shows dies into which a stack of flexible members may be fed inorder to produce a curved wall separator or a core with curves than canbe subsequently used as a panel in making other articles as mentionedhereinabove.

It will be seen that the dies 102 of FIG. l6 include upper die part 104and lower matched part 106. Similarly, in FIG. 17 the dies 108 may beused to produce a core or panel with but a single curve. Here the dies108 include an upper die 110 and a lower matched die 112.

It is therefore seen that the core of the present invention is composedof a series of thin, mildew resistant sheets superimposed one on theother and so formed to possess sufficient rigidity to be used as a partof a piece of furniture. The core preferably has a U-shape, althoughthis shape is but one of many shapes into which the core can be formed.

The method of the present invention involves applying a coating ofadhesive to at least one surface of a series of thin, flexible,uniplanar, mildew resistant sheets. This is followed by superimposingthe sheets, one on the other, to form a stack, and then applyingpressure to the stack to form the core. Where desired the topmost andbottommost plies can be a decorative face.

It follows that the present invention lends itself handily to abruptchanges in fashion or styling. The present invention is utilized to makea core than can be completed to provide the entire back for a chair orfor a detachable portion of the chair back. It follows that core membersof practically unlimited shape and sizes can be produced in accordancewith the present invention, and then completed to the whim of thedesigner. The core members of the present invention can be used not onlyin the manufacture of chairs, but can be used to provide other articles,again limited only by the imagination of the designer.

It can be seen that the attractive features of the present invention arepromoted by achieving a proper balance of the penetrating properties ofthe adhesive and the penetration resisting properties of the flexiblemembers by way of surface preparation. In this way a minimum of adhesiveis used, and hence drying time is less than 10 minutes and preferablyless than 1 minute.

Such speedy drying time is also achieved because the present inventionutilizes adhesives that set very quickly at nonnal room temperature (70F.). Also, with the present invention minimal pressure is usuallysatisfactory in making the core member. While FIG. I shows a moldingapparatus capable of exerting 200 p.s.i., a pressure of about 60 p.s.i.is preferred, and indeed even 25 p.s.i. has usually been satisfactory.

Without further elaboration, the foregoing will so fully illustrate ourinvention that others may, by applying current or future knowledge,readily adapt the same for use under various conditions of service.

What is claimed as the invention is:

1. In a method of manufacture of a core to be used in fumiture and otherarticles, wherein said method includes the steps of (a) prow'ding aplurality of flexible, uniplanar mildew resistant cardboard sheetshaving a thickness of about 1/32 inch to 76inch, (b) providing saidsheets with a smooth surface, (c) applying a coating of a roomtemperature setting adhesive to said smooth surface, ((1) superimposingsaid sheets, one on the other to form a stack and (e) applying pressureto said stack by matched dies at normal room temperature, theimprovement comprising applying a sizing coating to said smooth surfaceprior to the application of said adhesive coating in order to creategood water holdout properties in said cardboard sheets and thereby limitthe quantity of adhesive required as well as lowering the drying time ofadhesive in said stack to form a multiplanar core which is sufficientlyrigid and stiff to be used as a part of a piece of furniture.

2, The method of claim 1 wherein said pressure is applied to said stackin such a way as to form a U-shaped core.

3. The method of claim I wherein said pressure is applied by matchedpressure dies, exerting a pressure of 60 p.s.i.

4. The method of claim I wherein said steps of adhesive coating andsuperimposing of said sheets to form a stack are carried out byautomatic machinery.

5. The method of claim 1 wherein said adhesive is a tackified polyvinylalcohol adhesive.

6. The method of claim 1 wherein said sheets are of chipboard paper.

* t t i t

2. The method of claim 1 wherein said pressure is applied to said stackin such a way as to form a U-shaped core.
 3. The method of claim 1wherein said pressure is applied by matched pressure dies, exerting apressure of 60 p.s.i.
 4. The method of claim 1 wherein said steps ofadhesive coating and superimposing of said sheets to form a stack arecarried out by automatic machinery.
 5. The method of claim 1 whereinsaid adhesive is a tackified polyvInyl alcohol adhesive.
 6. The methodof claim 1 wherein said sheets are of chipboard paper.